Flexible, retractable extension tapes have long been known, and they are generally metallic, formed with a slight curve so that they can extend in a stiffened condition when withdrawn from a case or housing. Such devices are very efficient for measuring linear distances with no intervening obstruction.
There has also been well-known in the art a device generally referred to as a "tram gauge" which includes a rigid measuring rod, one end of which a telescoping arm may be fixed, and along the indicator/arm a second telescoping pointer can be slid so as to measure the distances between the tips of the two telescoping arms. Such device, however, is cumbersome because if the indicator arm is short enough to fit into a mechanic's toolbox, it is generally ineffective for measuring long distances and, contrarily, if the arm is long enough to be suitable for measuring large expanses, it will not fit into or easily be carried by a mechanic in his toolbox.
Other types of measuring devices such as calipers for accurately measuring small distances or flexible chain-like devices for measuring large dimensions such as 10 yards in a football field, are also well-known.
However, there has not been made available any device which combines the compactness of a flexible tape and the accurate telescoping measurements of a tram-gauge device.
U.S. patents relating to this general field include the following:
______________________________________ Bartlett 1,636,036 Jul. 19, 1927 Greenwood 2,571,569 Oct. 16, 1951 Odom 3,021,599 Feb. 20, 1962 Weiss 3,190,008 June 22, 1965 Cook 3,181,242 May 4, 1965 Maksim, Jr. 3,281,943 Nov. 1, 1966 Todd 3,289,306 Dec. 6, 1966 Anderson 3,390,461 Jul. 2, 1968 Quenot 3,680,214 Aug. 1, 1972 Schliep 4,227,314 Oct. 14, 1980 Scotese 4,989,341 Feb. 5, 1991 ______________________________________
Of the above-mentioned patents, Maksim U.S. Pat. No. 3,281,943 discloses a flexible extension tape for measuring irregular objects, but it does not include the telescoping devices of the present invention.
Quenot U.S. Pat. No. 3,680,214, particularly at FIGS. 8a, 8b and 8c show how a measuring tape can include a telescopic device.
The remainder of the patents are generally related to this field but, more specifically, to a non-retractable measuring instrument such as the tram gauge.
It is believed that there is no prior disclosure of a combination which includes a flexible retractable tape and telescoping measuring pointers, all of which can be compacted into a small device capable of being easily carried in a mechanic's toolbox and used for measuring extended distances over irregular obstructions.
Therefore, it is an object of the present invention to provide a retractable measuring tape with telescoping extension members permanently fixed thereto to enable a mechanic or similar worker to measure the distance between two points where there is an intervening obstacle.
A further object of the present invention is to provide a compact measuring device, including telescoping measuring points, the tips of which can be extended in position at the points to be measured, but wherein the measuring tape does not have to move in a straight line between the two positions to be measured.
Still another object of the present invention is to provide a measuring device similar to a "tram gauge", but which is flexible and can be collapsed into a very small space, so as to fit into a mechanic's toolbox.
With the above and other objects in view, further information and a better understanding of the present invention may be achieved by referring to the following detailed description: